Boat fender



March 1959 D. P. DOWN'EY 2,875,721

BOAT FENDER Filed Feb. 17, 1956 13 Fig. 7

INVENTOR. DIxan I? Dawney HIS A TTOR/VE Y5 desirable.

ted States Patent 2,815,721 BOAT'FENDER Dixon I. Downey, Franklin, Pa. .Appneanonrebruar 'fl, 1956, SerialNo; 566,276 splittin or. 114-219 Many. boat fendershavebeen developed to protect the hulls 'of boats and ships. Themost commontyp'e is a tubular bag or casing of woven material which is 'stulfed with a shock-absorbing material suchwas foam rubber orfabric. Such fenders possess a limited useful life sinceytheouter woven fabricis quite susceptible to rotting and splitting and the inner stufiing material is thus lost. Furthermore, such fenders are weighty and become waterlogged aa ae udrfioat ieadily. 'Otlierkhown fenders have air chambers of.the pneumatic type. Such devices are. also. of limited durabality.

This invention avdids the ditficulties of the prior art. Ihe prcsent fendr is constructed oflightweight, flexible, durable material which avoids thetendency to split. The plastic materials of construbtion are elastic and effectively cushion mews against boat or ship hills and at the same time provide a corrosion p'roof and easy-to-clean fender. Since it;contains no stufling materiahthe presentfender is ,virtually indestructible. Thelightweight and nonsinkability characteristics of this fender make it} further The fender may be made in numerous attractive colors which cannot wear off and do not stain or discolor the hull of the boat. Furthermore, the fender is relatively inexpensive to fabricate. In the drawings, I have illustrated a present preferred embodiment of my invention, in which:

Figure 1 is a plan view of the plastic boat fender;

Figure 2 is a cross section of the fender taken on plane 11-11 of Figure 1;

Figure 3 is a view similar to Figure 2 but illustrates a modification thereof;

Figure 4 is an end view of the fender shown in Figure 2;

Figure 5 is an end view of the modified fender shown in Figure 3;

Figure 6 is an enlarged end section of Figure 2;

Figure 7 is an enlarged end section of Figure 3;

Figure 8 shows a further modification of the fender; and

Figure 9 is a side elevation View of the modified fender illustrated in Figure 8.

A tube of plastic material 9 is cut to desired lengths and holes 10 are cut in the respective ends thereof. The cross section of the plastic tube may be of any desired shape. However, a cylindrical or oval configuration is preferred. The present application shows the fender fabricated from a tube of plastic of circular cross section. A second tube of plastic 11 is cut to the desired lengths, approximately the same length as tube 9, and holes 12 are cut in the respective ends thereof. The tube 11 is of a lesser diameter than the tube 9; however, the diiference in the respective diameters may vary depending upon factors to be described hereinafter. The tube 11 is inserted inside the tube 9 and the ends of the two tubes are flattened. The degree of flattening may vary; however, preferably the tubes are brought into a contiguous relationship as shown in Figure 2. Washers 13 are then positioned next to the hole 10 and a fastening means 13a here shown as a -gromin'et, is placed through the washers and the ends are swageate retainthejaides in the flattened condition. An end view ofjthisffender is shown in Figure 4. The grommets arepreferably made from brass or similar 'non-corroding material. Plastic material of sutficient rigiditymay also lie-used. flt apparent that each fender may contain any-numbe'rof grommets spaced alongits Ien'gthor at each end. Preferably the fastening means are hollow as: shownrhowever, solid means maybe used. I

A modification of the above fender is sliowniri Figure 3 in which the inside tube 14 is cut to aflen h less thau the length of the outside tube'9. 'The tube' 14 isinserted inside the'tube 9, 'the endsa r e flattenedand fastening means are aflixed"ther eon,- as-described above. Theflinf side tube 14' is 'held in a fixed 'position withinth. outside tube by frictionalcontact along surfaces '15. Figure 5 illustrates anend viewof this'fender. a

A "runner modification is showe in Figure 8 in which only one end of the'fen der is flattened. 1.The end16 is not flattened and thus "remains open. The end 17 is flattened by use of grommetsor similar meansias described above. A further modification of the fenders is shown by the use of a rope 18 used to maintaintli'e end of the ferider'in a flattened condition. 'It is not necessary touse grommets of any kind to protect the plastic or retain the endinfiattened condition when t em' e is used. However, to avoid any tendency of the plas'tic materialto tear, it is desirable to-inser't grommets in each hole in' the plastic tube ortubes. The rope maintains the end in flattened condition by being fastened in a small loop th'rough thewholes. 'J'I he 'use of a rope to retain one end of the fender in flattenedcondi'tion may be applied to either a singlertube 'or a double tube fender.

The above described fenders are self-draining of water or other liquid since one or both ends are open as shown by the openings 19 in Figures 4 and 5. However, it is possible to seal the ends of the fender by means of heat, solvent or mechanically, in order to provide sufficient buoyancy for use of the fender as a mooring float, emergency life-preserver, etc. Preferably at least one end of the fender is left open.

The fender may be manufactured from many materials including rubber, vinyl plastic, cellulosic-type plastic and others. However, polyethylene material seems to offer the most advantages for boat use, particularly since its specific gravity of approximately 0.93 allows it to float on water. Plastic materials do not become waterlogged. The fender can be manufactured in any color and either opaque or translucent. The color is integral and goes all the way through the material, thus avoiding a scufi'ed appearance on the fender. The wall section of the fender varies from A to /2" (or perhaps even greater) in order to furnish the degree of resilience and impact strength needed. The limitations on the wall thicknesses, and length, width, etc. of the fender are dictated only by industrial economies and ultimate use.

The major advantage of the present fender is that when it is subjected to extreme pressures or forces, it possesses an inner-resilient member 11 to absorb some of the shock. The outer shell 9 possesses suflicient resiliency to cushion slight or medium blows without marring the hull of the boat or ship. However, when the forces become sufliciently great, the outer shell 9 is pushed inwardly, and if the applied force continued to compress the fender, ultimately a split in the side might occur. However, the inner tube 11 becomes operative in resisting the intense shock prior to the time that splitting would occur in the outer shell 9. The overall fender thus possesses an ability to resist slight shocks without marring the article to be protected and also, it resists extremely heavy shocks without splitting. This type fender is very versatile due to its dual capacity. Thus, the diiference in diameters between the two tubes of plastic will depend upon their ultimate use and the resiliency and tendency to split in the outer shell 9. If the outer shell is of extreme toughness to resist some of the heavy shocks itself, the inner tube may be of a substantially lesser diameter than the outer tube and thus, would not become operative until extremely excessive forces had been applied to the fender. Conversely, if it is desirable to have the outer tube sensitive to slight shocks and thus of lighter material, the inner tube would have a diameter more closely approaching that of the outer tube to provide quicker reinforcement for severe shocks to avoid splittingthe outer tube.

The grommet on the end of the fender is installed in such a manner that contact between: it and the protected surface is avoided, even when the fender is considerably compressed. In other words, the grommet is installed below the effective contact surface of the fender as shown inFigures 4 and 5. Thus the surface being protected by the fender is not contacted by the grommets.

After the ends of the fender are flattened, the sides of the tubes of plastic assume a bowed effect as shown at 20 in Figure 1 but the top and bottom of the tube are bulged outwardly as shown by 21 in Figures 2 and 3. This peculiar geometrical shape enhances the ability of the plastic materials to absorb the intense shocks imparted to the fender without splitting the latter. But the overall design of the fender is simple which permits the use of relatively inexpensive polyethylene tubing as a raw material. After the fender is pressed inwardly by extreme pressures, the parts readily return to their original shape. Other fenders slit if stulfed or burst if they contain a sealed air chamber.

The fender may be produced in any desired length or end configuration. Elongated sections of the fender may be used as a protector for piers and piling which boats come in contact with.

While I have described the present preferred embodi- .4 ment of my invention, it is to be understood that it may be w se. m o ie w th n... he. scope. saith; .tollowins claims.

I claim:

1. A boat fender including a first elongated plastic tube, a second elongated plastic tube disposed inside said first tube, at least one end of the first tube being flattened by moving two diametrically opposed points on the end into close relationship with each other, an end of said second tube being clamped within the flattened end of the first tube, and means to retain the first tube in flattened condition.

' 2. A boat fender described in claim 1 wherein thesec- 0nd tube is shorter than said first tube. I h

3. A.boat fender described inclaim 1 wherein both ends of the first tube are flattened.

4. A boat fender described in claim 1 wherein said tubes are the same length.

5. A boat fender described in claim 1 wherein both ends of the first tube are flattened; the sides of the tube are bowed inwardly and the top and. bottom of the tube bulges outwardly.

6. A boat fender described in claim 1 wherein grommets pass transversely through the end of the tube to retain it in flattened condition.

References Cited in the file of this patent- UNITED STATES PATENTS 

